Chitosan-based film-forming systems with cannabidiol: a novel topical strategy for antimicrobial therapy

Innovative topical drug delivery systems, such as film forming systems, aim, among other objectives, to offer new application possibilities, enhance patient compliance, and provide prolonged therapeutic effects. This study presents the development and comprehensive characterization of a novel chitosan-based film-forming system incorporating cannabidiol for antimicrobial topical treatment. While chitosan and cannabidiol have been separately explored for their pharmaceutical properties, their combination within an in situ film-forming matrix remains largely unreported. Chitosan was chosen for its film-forming, mucoadhesive, and inherent antimicrobial properties. Ethanol-water ratios enabling optimal solubilization of chitosan were determined, and a suitable cannabidiol solubilizer was identified to ensure its homogeneous incorporation into the polymer matrix. The resulting films were characterized using differential scanning calorimetry, rheological analysis, Raman spectroscopy, optical microscopy, and scanning electron microscopy. In vitro studies demonstrated sustained cannabidiol release, favorable mechanical properties, and excellent antimicrobial efficacy against both Gram-positive and Gram-negative bacteria, as well as fungi. These results highlight the developed film-forming system as a novel and promising platform for the localized treatment of bacterial and fungal skin infections.